Iron ore is a strategic mineral resource of World War I with wide utilization and large consumption. However, in the process of iron ore development, the resulting iron tailings also increase year by year, which inevitably brings a series of problems and further stimulates the development of iron ore tailings treatment and comprehensive utilization.
At present, there are three common methods for the treatment of iron ore tailings: first, re concentration of iron ore tailings and secondary recovery of minerals with recovery value in tailings; The second is to dry discharge the iron ore tailings, and the tailings after dry discharge can be reused; The third is to fill the goaf with iron tailings.
Tailings re concentration
According to the different properties of iron tailings, magnetic separation and gravity separation are often used to recover and reselect the minerals with recovery value in the tailings.
Some iron in iron tailings exists in magnetite and weakly magnetic hematite and limonite, while gangue minerals are mainly non-magnetic quartz and calcite. The magnetic difference between them determines that magnetic separation can be used to recover iron from tailings.
After 2-3 stages of magnetic separation, if the high gradient magnetic separation method is used for preconcentration of magnetic minerals, it is used in combination with the shaking table process or centrifuge process of gravity separation method to obtain iron concentrate or ferrotitanium concentrate.
In the gravity separation method used for there separation of iron tailings, the spiral chute is used for the pre tailing of iron tailings, and the shaking table is used for the re separation of high-intensity magnetic separation concentrate. When processing fine-grained ore, the concentrate recovery rate of the shaking table is low. At this time, the centrifuge can often be used with strong magnetic separator, which is suitable for the quality improvement of grade 35-45 iron secondary concentrate.
Tailings dry discharge
There are two main methods for discharging tailing iron: wet discharge and dry discharge. Among them, wet discharge of tailings is a traditional way of tailings discharge, which has many hidden dangers and has been gradually eliminated. Tailings dry discharge is a new tailings treatment process rising in recent years, which alleviates the capacity pressure of tailings pond, reduces the potential safety hazards of the tailings pond, and increases the means of tailings reuse.
Generally, the tailings dry discharge process system is mainly composed of a slurry pump, hydrocyclone, high-efficiency transformation thickener, high-frequency and high-efficiency dewatering screen, box filter press, and pulp conveying device.
In recent years, with the rapid development of filling mining methods and filling technology, the treatment of tailing iron in tailings filling stope has also been widely used for ecological restoration. In view of the fact that some mine terrain is not suitable for the construction of tailings pond, filling the goaf with iron ore tailings provides an effective and economic method.
The above are the common treatment methods of iron ore tailings. Optimizing the treatment of iron ore tailings and comprehensively recovering and utilizing them can make more full use of mineral resources and realize the effective unity of resource benefits, economic benefits, social benefits and environmental benefits. In practical application, it is suggested to comprehensively consider the nature, scale and return on investment of tailing iron to determine the suitable treatment and comprehensive utilization method of iron ore tailings.